L2TP(Layer 2 Tunneling Protocol)

L2TP(Layer 2 Tunneling Protocol) is an industrial standard Internet tunnel agreement, function and the PPTP protocol roughly similar, such as network data flow can also be to encrypt. But there are also differences, such as the PPTP requirements for IP networks, network L2TP request packet oriented point-to-point connections, Use a single PPTP L2TP use multiple tunnel, tunnel, L2TP provide baotou compression, tunnel validation, while the PPTP no support.

Brief introduction

L2TP agreement is draft, by IETF Ascend, Cisco and Microsoft, 3COM companies such as the participation of bilevel formulation tunnel agreement, which combines the PPTP and L2F two second tunnel agreement advantages, to numerous companies, has become the IETF accepted by relevant layer 2 channel agreement industrial standard, based on Microsoft point-to-point tunnel PPTP protocol () and Cisco layer 2 protocol (L2F yoursuccess forwarding, being an Internet service provider and companies use make this virtual private network operations can through the Internet.

Main application

In VPN connections to set L2TP connection, method with the PPTP VPN configuration, also in VPN attribute window "network" TAB, VPN type on "L2TP IPSec VPN" can.

Second tunnel protocol (L2TP) is used to integrate multi-protocol dial-up service to the existing Internet service providers points. The PPP defines multi-protocol cross second point-to-point link a encapsulation mechanism. Specifically, the user through the use of numerous technical one (e.g. dialling plants, ISDN, ADSL, etc) to acquire second connected to the network access server (NAS), and then in this connection to run on PPP. In this configuration, the second ZhongDuanDian and PPP session end point in the same physical device (such as: NAS).

L2TP expanded the PPP models, allowing the second and the PPP end in different by packet switching network interconnection equipment to. Through L2TP, users in the second connected to a visit concentrators, (e.g. modem pool, ADSL DSLAM etc), then the concentrators, will separate the PPP frame tunnel to NAS. Such, can put the PPP packet of practical processing process and L2 connected end separated.

For such of separation, its apparent a benefit is that L2 connection can be in a (local) circuit concentrators, termination, then on through sharing network as frame relay circuit or Internet extended logic PPP session, instead of the NAS on termination. From the user's perspective, directly on the NAS termination L2 connection and use L2TP no functional difference. L2TP protocol is used to solve the "more connected couplet selected groups of separation" problems. Many links PPP, generally used to concentrate ISDN B channel, need constitute more than all the links to bind channel in a single network access server (NAS) on combination. Because L2TP makes the PPP session may occur in receiving session with the physical point outside of the position, it is used to make all the gateway appeared at a single NAS and allows multiple links operation, even in physical contact scattered in different physical location on the NAS.

L2TP web Server (LNS said L2TP a Server), is the PPP end system used for processing L2TP protocol Server part of the equipment. It as L2TP tunnel on the other side of the endpoints, is the LAC end-to-end equipment, was LAC tunnel transmission PPP session logic termination endpoints.

Information types

L2TP use the following two information types, namely control information and data information. Control information used in tunnel and call the set up, maintain and cleared. Data information for packaging tunnel carried by the PPP frame. Control information using L2TP in a reliable control channels to ensure sent. When there is a packet is lost no forwarding data information.  

10 minutes Rope speed made hot stature

Step1 jinji independence

Will rope converted into appropriate length, the hands hold of the rope ends; Stand, right leg forward half step, left leg bent on his right foot inside position, the hands hold rope by chest, and will try to lift on rope pulling into and ground is 45 degrees of straight, maintain 5 seconds, then change leg, repeat 5 groups.

Thin body effect: minus his thighs redundant adipose, grow to double arm, and help forceful figure.

Step2 accept waist high

Her legs spread apart to stand, and shoulder are the same as wide, Will rope converted into appropriate length, clasped in chest; rope ends Keep my feet motionless, the upper left turn, accept the waist to hold out a bosom, maintain pose 5 seconds. Switch sides, then repeat 5 groups.

Thin body effect: the shaping sexy waist line, minus the arm dewlap, also can reduce the shoulder, back unwell feeling.

Step3 side SLR

Side lies on the floor, his legs bent; Upper body carried from the ground, left arm hold to, the right hand hold the string, With rope hook live right leg, try to elevate legs until with ground in a straight line, and cooperate with breathes out, then change leg repeat 5 times.

Thin body effect: can be a very good exercise abdominal muscle, waist muscle and before the chest muscles, meanwhile to the upper limbs also have very good shape effect, and can grow to arm. 

To strong and handsome calcium cannot little

The body to have enough calcium intake, just can have enough calcium salt deposits in bone. According to research, bone strength is mainly in 12 to 18 years to the formation of that human bone peak and calcium intake when young close relations. If missed the opportunity, did not develop into a stronger bones, not only affect height, it will also increase its old age develop osteoporosis danger. Short, rachitic body nature is and strong and handsome antipathetic.

If long-term calcium, eyeball decreased elasticity, marbling grading of contractive function is bad, make some people appear eye big have god's phenomenon, or premature canthus wrinkle, still easy to produce myopia.

Calcium can affect nerve muscle coordination. When nerve around converted in calcium ion concentration drops, nerve excitement sex will increase significantly, can appear be agitated, hyperactivity, insomnia, brothers and sisters and tingling, muscle convulsion, waist ache symptoms.

Calcium can make the cell membrane permeability increase. Calcium ions to maintain the integrity of the cell membrane has an important role, low calcium state can make the skin and mucous membrane permeability increase of water, make the skin elasticity decreased, appear unexplained itchy skin, edema and skin urticaria.

Young females in pregnancy during the whole process, takes 20 to 30 grams of calcium, on an average day about pay 100 milligrams. Gestational calcium, vascular smooth muscle tension is increasing, it is one of the important reasons for pregnancy-induced hypertension, and will affect fetal developing normally.

Now young women lack calcium phenomenon was increasing, reason has the following aspects:

One is to drink coffee become fashion, and coffee can stimulate adrenal cortical, make urine output increased. The coffee adenosine also can accelerate calcium from urine discharge.

Secondly, young girls love "beauty" fear fat, many people don't eat pork liver, soybean milk, and love to eat relaxing snacks, inadequate intake of calcium.

The third was afraid bask, caused by inadequate vitamin D synthesis. Now think that young women calcium basic measures should be seriously food intake, which should with milk for human body the best source of calcium. Research shows that female youth drink milk than do not drink milk height increase 5 centimeters, higher than 6%, concludes BMD from 28% down to 0.  

Lithium Battery

Lithium battery is a kind of lithium metal or by aluminium-lithium alloys for anode materials, instead of using water electrolyte solution of batteries. The earliest lithium battery from great inventor Thomas Edison, use the following response: Li + MnO2 = LiMnO2 this reaction for REDOX reaction, discharge. Because the chemical properties of lithium metal very lively, making lithium metal processing, storage, use of environmental requirement is very high. So, lithium battery long-term didn't get applications. Now lithium battery has become the mainstream.

Lithium battery principle profile

summary

Lithium battery is a kind of lithium metal or by aluminium-lithium alloys for anode materials, instead of using water electrolyte solution of batteries. The earliest lithium batteries used the following response: Li + MnO2 = LiMnO2, this response for REDOX reaction, discharge.

The positive reaction to occur on

LiCoO2 = charging = Li1 - xCoO2 + Xli++ Xe (electronic)

Negative reaction to occur on

6C + XLi++ Xe = = = = = LixC6

Battery total response: LiCoO2 + 6C = Li1 - xCoO2 + LixC6

Lithium battery development process

Because the chemical properties of lithium metal very lively, making lithium metal processing, storage, use, to environment require very high, so lithium battery production in special environment conditions. But because of lithium battery of a lot of advantages, lithium batteries were widely used in electronic instrument, digital and electrical appliances product. But, lithium battery majority is secondary battery, also have non-rechargeable batteries. A few of the secondary battery life and safety is poorer.

Later, SONY of Japan invented by carbon materials for anode, with li-containning compounds for positive lithium battery, in the process of charging and discharging lithium metal, not only exist, lithium ion, this is the lithium ion batteries. When the battery charge, battery anode has lithium ion to generate, generated by the electrolyte of lithium ion movement to the negative terminal. But as the cathode carbon is layered structure, it has a lot of microporous, reach of negative lithium ion is embedded into carbon layer of microporous, embedded lithium ion battery capacity more higher. Likewise, when to the battery for electric discharge (i.e. we use battery process), anode carbon layer embedded in the lithium ion emerge, and movement back positive. Back positive lithium ion, the more discharge capacity is higher. We usually say of battery capacity meant discharge capacity. In Li - IO of charging and discharging lithium ion in the process, from the positive - negative - positive motions. Li - like a rocking chair Batteries IO, rocking chair at both ends of the battery, and for the extremes of lithium ion is like the players do in rocking chair return rush. So Batteries and call Li - IO rocking chair type battery.

Along with the digital products such as mobile phones, laptops and other products widely used, lithium ion battery with excellent performance in this kind of product is widely used in recent years, and gradually to the other application development. In 1998, tianjin power institute started commercial production of lithium ion battery. Traditionally, people lithium ion battery also called lithium battery, now lithium ion battery has become the mainstream.

Lithium battery material

Lithium battery cathode materials can be divided into the following kinds:

The first kind is carbon anode materials:

At present already practical for lithium ion battery anode materials are basically carbon materials, such as artificial graphite, natural graphite, intermediate phase carbon microspheres, petroleum coke, carbon fiber, pyrolytic resin carbon, etc.

The second is tin base anode materials:

Tin base anode materials can be divided into tin oxide tin and matrix composite oxides two kinds. Oxide refers to all valence metal tin oxide. No current commercial products.

The third one is li-containning transition metal nitrides anode materials, and there are no commercial products.

A fourth is alloy anode materials: class

Including tin base alloy, silicon base alloy, ge base alloy, aluminum alloy with, antimony base alloy, magnesium alloy with and other alloy, and there are no commercial products.

A fifth is nanoscale anode materials: carbon nanotubes, nano alloy materials.

The 6th kind of nanomaterials are nano oxide material: currently, hefei xiang is chemical technology Co., LTD. According to 2009 lithium battery new energy industry market development, the latest trend, many companies have begun to use nanometer titanium oxide and nano silicon oxides added in the old traditional graphite, tin oxide, carbon nanotubes inside, greatly increase the lithium battery of blunt blunt discharge put of electricity and often.  

Relay

Basic information

Relay is a transmission channel between two points, both of which are usually exchange center. Trunks are carrying multiple logical link of a physical connection. Along with the science and technology development, relay concept is not only applied in wireless communication, network communication switch trunk can also call a relay.

principle

The basic principle of relief theory is at the end of the 19th century mathematicians Erlang proposed, Danish study how he devoted himself to the limited service capacity for a lot of customer service. Now, use his name as traffic intensity of the unit. A Erlang said a fully occupied in a channel traffic intensity (i.e. unit hours or unit minutes of call duration). For example, a in one hour occupied a 30-minute channel traffic for 0.5 Erlang.

Wireless communications, relay concept refers to allow large number of users in a village in relatively small number of Shared channel, namely from available channel repository to give each user on-demand channel.

In relay wireless systems, each user just in a call when it allocate a channel, once call terminated, originally occupied by the channel immediately return to available channel repository.

According to user behaviour statistics, relay make fixed number of channels or lines can be a quantity greater, random user community service. Telephone company according to relay theory to decide which has hundreds of thousands sets telephone office building of the number needed distribution circuit. Relay theory is also used in cellular wireless systems design, in the available telephone lines in a contact number and peak no lines are available between the possibility of a compromise. When the telephone lines declined, for a specific user, all line busy all the possibility of bigger. In relay of the mobile wireless systems, when all wireless channels are occupied and users and, when they occur to request service call obstruction or system refuse access. In some systems, may use queuing ways to keep is asking conversation user information, until one channel so far.

Basic term definition

Relay theory used in basic terms definition:

Build time:

Give the user is asking to allocate a relay radio channel of time required

Obstruction call:

Because of congestion cannot finish in the request of the call, also called loss call

Keep time:

A typical call the average time to maintain, expressed as H (in seconds for the unit)

Traffic intensity:

Characterization channel availability, efficiency, and the average occupancy rate for channel to Erlang for the unit. It is a dimensionless value, usable to represent the single or multiple channel availability. Expressed as A

Load:

The whole system of traffic strength to Erlang for the unit

Service level (GOS) :

The amount of characterization congestion level, defined as a call blocking probability (expressed as B, the unit is Erlang), or delay time more than one particular time of the probability (expressed as C, the unit is Erlang)

Request rate:

Unit time average call requested times. Expressed as l/SEC

The stock of the rise in relief

Banker in pull litre share price, discover cast dish is overweight, to cleanse them from these float to prepare, need a wash dish finishing process, in K line represents a box-like finishing shape, in share price on expression is fluctuate and we put the finishing form called up relay form. 

Belt

Protects the waist, also called a belt, protect belt. In sports, beam on the waist to protect the waist from harm, heat preservation, or some special function of the band. In sports, often because of the excessive waist muscle resistance, high intensity exercise resistance of bearing and nervous, have acerbity keenly feel. Wear suitable materials and specifications of protects the waist can effectively protect the waist organization, prevent sports injury.

Basic introduction

Generally by can breathe freely waist protect a net, quality high elastic strap around by the xiamen poly (DE with industry Co., LTD. Provide), strengthening belt, spandex etc is made, hidden inside half hard alloy bars or medical fiber plastic pieces, supporting and fixing spine and contract abdomen away force and peel strength excellent magic stick, ensure care he could and long-term safety is used, facilitate adjustment protect's size and increase abdominal pressure tightness, reduce the lumbar bearing, limiting the lumbosacral vertebral activities, ease the pain, auxiliary physiotherapy rehabilitation of unique design, allergy, good air permeability, wear comfortable, tense-lax free adjustment of the spine waist has certain protective effect.

Edit this paragraph apply disease

1. The bone spur, lumbago, sciatica diseases such as rehabilitation and treatment.

2. Lumbar disease, waist accumulate strain lumbar syndrome prevention and auxiliary treatment;

3. After lumbar spine surgery or lumbar intervertebral disc herniation and rehabilitation of stability,

4. Physical labor and aging virtual person of the waist protection and support,

5. Eliminate or alleviate because of work force or fatigued waist and abdomen, back of discomfort.

6. Can be used for winter field protects the waist and women postpartum accept stomach and abdominal partial interceded receive an abdomen, to keep fit strong and handsome.

Basic function

First, the pressure. Put some pressure on muscle, adjust the motion force equilibrium. To a certain extent, strengthen muscle strength, reduce swelling. Muscle in athletic process stimulated, metabolism, and muscle cells of water increases amount, causing cell can have the feeling, proper inflation pressure helps make sport more relaxed powerful.

Second, support. A hard protects the waist can in athletic process, provide certain volume, torre live kinking excessive waist, reduce its muscles were, protect the waist won't sprain or ache. Some functional of protects the waist back with tinsel, can provide the big support effective, avoid accidental injury, this protects the waist back of the general higher.

Third, heat preservation. Double or layers of material very soft and comfortable protects the waist with strong heat preservation function. Athletes playing sports wear less, and often more, easy to catch cold catch cold heat waist, make the person waist sour, spasm or cause stomach discomfort. Insulation performance of protects the waist can effectively protect the waist temperature, accelerate the blood circulation and prevent colds and stomach some discomfort.

Fourth, fitness. Strengthen cell metabolism, burning fat, adjust tightness degree, exert the proper pressure help weight-loss. In working with the waist related movement, compression, insulation absorbent protects the waist adipose decompose, can speed up the waist is collecting the fitness of necessary guards.

The basic principle

Good protects the waist can not only fixed waist, warm, still can release far-infrared anions continuously. And brought to the body micro electric current thermoelectric stimulating effect. Can effectively improve blood circulation and ease muscle fatigue, activate cells, promote metabolism, regulate channels qufeng dehumidification and analgesic to cold, enhance organism disease-resistant ability. Product safety, use convenient, effect of lasting.

Use crowd

1, the waist dish outstanding, lumbar hyperplasia, displacement, lumbar muscle strain and siatic nerves and so on many kinds of lumbar disease and after the operation of rehabilitation crowd,

2, are engaged in however, start-up and old lumbar degenerative diseases, flax acid bilges cold sore crowd,

3, lumbar abdomen hypertrophy lumbar pain, postpartum lumbar deformation women, lumbar pain crowd,

4, after 35 to avoid lumbar deformation, dislocation, partake lumbar pressure;

Five, wind cold dampness polio-free, waist sour pain, numbness fatigue, lumbar muscle strain, soft tissue damage, hyperosteogeny, traumatic pain, the crowd,

6 and applicable for coach drivers etc long time maintain same postures work crowd.

Method of use

1, PingWo, will this belt cushion on the waist, clasp buckle at abdomen before, adjust on both sides of the elastic to comfortable position.

2, while standing straight waist, as far as possible to the waist belt pad in after clasp buckle at abdomen before, adjust on both sides of the elastic to comfortable position.

Basic categories

Ordinary warm protects the waist

This protects the waist with cotton, wool material is given priority to, also add leica, polyester, polyamide fiber etc increase elasticity. This kind of protects the waist main function in warm, cashmere warmth retention property best, but this kind of material defect is in auxiliary fixed waist performance is poor. And, because of the sultry relations in the summer and autumn unusable. In addition, to fashion rangaimei ladies, because the thickness of the relationship, wear is bloated, affect coat close-fitting, beautiful.

Add magnet or activated carbon spontaneous hot protects the waist

This protects the waist with spontaneous heat and protection function, add a magnet and human interaction send out quantity of heat, human body during the cold seasons get continuous heating, obtaining a lot of consumer's favorite. However, these activated carbon or magnet itself exists life cycle, time grew, calorific performance will be reduced. In addition, activated carbon or spontaneous hot not according to the human body their own needs and comfort to adjust, can let the human body heat excessive sweating, sweat savings in protects the waist of material in the difficult to send out out and meet wind will make joints where temperature acceleration decreased, joint discomfort is aggravating, is not good for summer use.

Electrothermal protects the waist

This protects the waist general set up inside the store warming function, generally can be used on 6 ~ 12 hours, and its safety, warm and convenient characteristics get many consumers, however, this kind of product can't use anytime and anywhere, nor free to adjust temperature in the functional design are often in order to take care of electric heating function and unable to take care to human engineering design, in auxiliary waist immobility, restore the waist, the body's natural curve function design deficient, nature is not good for summer use. 

Have eggs for breakfast help reduce weight

American researchers have found that have eggs for breakfast can help people to reduce day caloric intake of, be helpful for reducing weight. This is because eggs are rich in protein, easy to make people feel fuller, thus reduce appetite.

Connecticut state university researchers in the nutrition research magazine published reports say they on different days to 21 male volunteers provides two heat the same breakfast. A consists of three egg scrambled eggs and a piece of toast, another copy composed by a hard bagel, half spoon low-fat butter and six-ounce ($170 grams) low-fat yogurt composition. After three hours, researchers for volunteers arranged for lunch buffet breakfast, lunch for egg calories than the average person eat solid bagel less 112 calories.

From a long day calories look, the former is less than the latter consume about 400 calories. Lead researcher professor said maria fernandez, volunteers blood test results and their subjective feelings are shown, edible which eggs primarily after breakfast, people relatively easy felt hungry. In previous of another study, researchers to overweight volunteers providing with the above experiment similar breakfast. The results have eggs for breakfast people have reduced the weight than eat more hard bagel 65%, and more energetic than the latter.

People once thought, eat more eggs can lead to high cholesterol levels, increase your chances of a heart attack. But British researchers found that food contains many may affect the cholesterol levels substance, which plays the leading role is meat in saturated fatty acids. British egg industry association says, for most people, one day eats to two eggs will not lead to high cholesterol levels.